1. Field of the Invention
The present invention relates to an endoscopic surgical instrument for treating an object such as a blood vessel.
2. Description of the Related Art
Recently, cardiovascular bypass surgical sometimes uses, as a bypass blood vessel, a lower limb blood vessel such as a great saphenous vein or a upper limb artery such as radial artery of the patient himself/herself. A living tissue harvesting surgical system is used to harvest this blood vessel under endoscopic observation.
This living tissue harvesting surgical system includes an endoscopic surgical instrument which treats an object (living tissue) such as a blood vessel and an endoscope inserted into the endoscopic surgical instrument.
A harvester which is an endoscopic surgical instrument is a tool including a bipolar cutter for electrically cauterizing and cutting branches of a blood vessel.
The tip part of this bipolar cutter is provided with a groove and a pair of electrodes arranged on the upper and lower sides of the groove. When the bipolar cutter moves forward, an electric discharge occurs between the two electrodes to coagulate and cut branches entering the groove while stopping bleeding. The cutter apparatus of the bipolar cutter is made of a ceramic or synthetic resin such as polycarbonate which is a transparent member.
Such surgical apparatuses are disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication Nos. 08-317935, 2003-305054, 2006-326157, and 2006-280662, Jpn. PCT National Publication No. 2000-502585, and Jpn. Pat. Appln. KOKAI Publication Nos. 2000-70280, 2001-61848, and 2005-261945.
Jpn. Pat. Appln. KOKAI Publication No. 08-317935 discloses an electrosurgical method and apparatus which optimize tissue surgical energy efficiency by providing electrodes which can be selected in accordance with the type, thickness, and impedance of a tissue to be engaged or treated by an end-effect device or other parameters.
Jpn. Pat. Appln. KOKAI Publication No. 2003-305054 also discloses an electrosurgical apparatus free from wasteful power consumption.
Jpn. Pat. Appln. KOKAI Publication No. 2006-326157 discloses an endoscopic surgical instrument and endoscopic surgical instrument system which allow one to perform surgical incision and surgical coagulation while quickly and selectively using electrode sections having shapes suitable for the respective surgeries and reduce the load on patients by saving cumbersome operation and shortening the operation time.
Jpn. Pat. Appln. KOKAI Publication No. 2006-280662 discloses an electric surgical instrument which provides a non-slip effect between a living tissue and an incision electrode to facilitate the capture of a living tissue to be incised and can reliably incise only a target region with a high-frequency current.
Jpn. PCT National Publication No. 2000-502585 discloses an apparatus and method for electrosurgery.
Jpn. Pat. Appln. KOKAI Publication No. 2000-70280 discloses a high-frequency surgical instrument which can prevent electrical short circuiting between a pair of grip members and allows reliable coagulation and incision of a tissue.
Jpn. Pat. Appln. KOKAI Publication No. 2001-61848 discloses a high-frequency surgical instrument which is suitable for the incision and excision of an intraoral tissue such as a palatopharyngeal tissue and can safely and reliably coagulate and incise a surgical target tissue without any bleeding.
Jpn. Pat. Appln. KOKAI Publication No. 2005-261945 discloses a biopsy apparatus including a hemostatic electrode which coagulates a living tissue.